1. Field of the Invention
Embodiments of the invention relates to the field of display technique, and especially to a shift register unit, a shift register comprising the shift register unit and the scanning method thereof, and a display device.
2. Description of the Related Art
In digital circuits for a liquid crystal display (LCD) device, thin-film transistor drivers mainly comprise gate line drivers and date line drivers. The gate line drivers are configured to convert the inputted clock signal via shift registers, and apply the converted signal to the gate line of a LCD device. The shift registers are positioned in the gate line drivers of the LCD device, each gate line is connected to one sub-circuit of the shift register, and drive signal is provided to the gate line via the gate line driver.
In prior art, traditional shift register scans in one direction. To scan in both directions, two those shift registers for scanning in one direction should be connected together based on mirror principle. However, the structure of the shift register that can scan in both directions is usually very complicated because so many thin-film transistors, for example, 20 to 30 thin-film transistors, are used in the shift register. To properly arrange those thin-film transistors is time-consuming and cost-wasting. Besides, large coupled noise voltage is generated between the thin-film transistors, such that the performance of the shift register is affected.